Pakkaus

import java.util.*;
import java.util.regex.Pattern;

public class Pakkaus {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		String input = scanner.nextLine();
		StringBuilder out = new StringBuilder();
		
		int kerroin = 0;
		String kerrattava = "";
		boolean numeroitaTullut = false;
		
		for (int i=0; i<input.length(); i++) {
			char c = input.charAt(i);
			
			if (c >= '0' && c <= '9') {
					
				if (numeroitaTullut) {
					while (kerroin > 0) {
						out.append(kerrattava);
						kerroin--;
					}
					kerrattava = "";
					kerroin = c-'0';
					numeroitaTullut = false;
				} else {
					kerroin = kerroin*10 + (c-'0');
				}
			} else {
				numeroitaTullut = true;
				kerrattava = kerrattava + c;
			}
		}
		
		while (kerroin > 0) {
			out.append(kerrattava);
			kerroin--;
		}
		
		System.out.println(out.toString());
	}
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED